Button cell with multifunctional coating

Abstract

This invention discloses a button battery with a multifunctional coating, comprising a battery casing consisting of a positive electrode shell, a sealing ring, and a negative electrode cap. The outer end of the positive electrode shell is bent inward to form a bent section. The outer surface of the bent section of the positive electrode shell, the outer end face of the sealing ring, and the outer peripheral surface of the negative electrode cap are sequentially connected to form an R-angle transition joint surface. A multifunctional coating is circumferentially coated on the R-angle transition joint surface along the battery. The liquid adhesive of the multifunctional coating is prepared by mixing the following raw materials in parts by weight: 52-75 parts of acrylate prepolymer; 15-45 parts of acrylic monomer; 0.5-5 parts of photoinitiator; 0.05-0.2 parts of leveling agent; and 0.4-5 parts of repellent. This invention achieves a triple effect of sealing enhancement, insulation protection, and prevention of accidental ingestion by applying a multifunctional coating at the R-angle transition joint surface, simplifying the process and saving materials and processing costs. Furthermore, the coating is an oil-based coating, and the repellent is not easily washed away during long-term use.

Description

Technical Field

[0001] This invention relates to the field of button batteries, and more particularly to a button battery with a multifunctional coating. Background Technology

[0002] Button batteries, with their advantages of being lightweight and compact, are widely used as power sources in various microelectronic products. Conventional button batteries are sealed mechanically; specifically, this involves bending the edge of the positive electrode casing inwards, compressing the sealing ring between the positive and negative electrode caps, and relying on the elastic deformation of the compressed sealing ring to ensure a tight seal between the bent edge of the positive electrode casing, the sealing ring, and the negative electrode cap, thus achieving a physical seal. However, the existing structure still has significant drawbacks: (1) Button batteries are small and smooth, making them easy for children or pets to accidentally ingest. After the battery enters the body, the metal casing is easily corroded and squeezed by digestive fluids and can be damaged. The internal acidic or alkaline electrolyte can leak, which can severely corrode the digestive tract mucosa, leading to poisoning and organ damage. In severe cases, it can cause fatal injury. (2) Button batteries are semi-sealed structures. Even if the sealing ring is tightly fitted to the positive electrode shell and negative electrode cover after normal sealing, a small amount of electrolyte may still leak during long-term use or storage due to factors such as aging of the sealing ring and temperature changes. When the leaked electrolyte comes into contact with moisture in the air, it can easily cause corrosion of the battery shell and the formation of green mold on the surface, affecting the reliability and service life of the product.

[0003] To address the aforementioned risk of accidental ingestion, existing technologies (such as CN120082245A) achieve the anti-ingestion effect by coating the outer surface of the battery with a coating containing a bittering agent. However, traditional bittering coatings have limited functions and are mostly water-based, resulting in poor adhesion and easy peeling off when exposed to water.

[0004] To address battery leakage and mold growth on the casing, existing solutions typically involve applying and curing UV adhesive at specific points in the joint between the positive electrode shell, the sealing ring, and the negative electrode cover. This dense adhesive layer seals the micro-gaps in the assembly, preventing moisture and air from entering, thereby improving sealing and inhibiting the growth of green mold.

[0005] Currently, the anti-ingestion coating and the sealing and mildew-proof UV adhesive in the industry are two independent functional layers that need to be processed and formed in separate steps. This not only increases the battery manufacturing process but also raises material and processing costs, which is not conducive to mass production simplification. Summary of the Invention

[0006] The purpose of this invention is to provide a button battery with a multifunctional coating that can simultaneously achieve the triple effects of sealing enhancement, insulation protection, and prevention of accidental ingestion through a single adhesive coating process.

[0007] The technical solution to achieve the purpose of this invention is: a button battery with a multifunctional coating, comprising a battery shell composed of a positive electrode shell, a sealing ring, and a negative electrode cover. The outer end of the positive electrode shell is bent inward to form a bent section, and the sealing ring is pressed inward by the bent section to achieve a sealed fit between the positive electrode shell, the sealing ring, and the negative electrode cover. The outer surface of the bent portion of the positive electrode shell, the outer end face of the sealing ring, and the outer peripheral surface of the negative electrode cover are sequentially connected to form an R-angle transition connection surface. A multifunctional coating is provided on the R-angle transition surface; the multifunctional coating is applied circumferentially along the battery circumference. The liquid adhesive for the multifunctional coating is prepared by mixing the following raw materials in parts by weight: 52-75 parts of acrylate prepolymer; 15-45 parts of acrylic monomer; Photoinitiator 0.5–5 parts; Leveling agent 0.05–0.2 parts; 0.4–5 parts of an aversive agent; The photoinitiator, leveling agent, and antagonist mentioned herein are all conventional commercial additives.

[0008] This invention imparts an anti-ingestion function to UV adhesives by adding an antagonist to an oil-based acrylate UV adhesive system. It also breaks with convention by spraying liquid UV adhesive (i.e., the liquid adhesive of the multifunctional coating) onto the rounded corner transition surface of a coin cell. To ensure stable adhesion of the UV adhesive at this location, the proportions of each raw material component of the UV adhesive are optimized. The adjusted amount of acrylate prepolymer is 52–75 parts, significantly higher than the conventional 20–50 parts. The amount of antagonist added is mainly affected by its solubility, and is controlled at 0.4–5 parts by weight. Through optimized adjustment and precise control of the amount of each raw material component, when the liquid UV adhesive is uniformly applied circumferentially to the rounded corner transition surface of the coin cell using a dispensing machine, the adhesive spreads naturally along the circumference of the cell, forming a continuous and smooth arc-shaped adhesive surface. The coating morphology is uniform and regular, without local agglomeration or jagged coating defects. Simultaneously, the free radicals generated by the photoinitiator can initiate the ring-opening polymerization of the double bonds of the acrylate prepolymer and acrylic monomer, forming a three-dimensional cross-linked network to complete the curing of the adhesive. The surface repellent is tightly bound to the three-dimensional cross-linked network, making it difficult to detach or be lost. The inner repellent is encapsulated by the three-dimensional cross-linked network and will be continuously released when the coating is damaged by chewing. Furthermore, after curing, this liquid UV adhesive has excellent adhesion, thus forming an integrated multifunctional coating with sealing, insulation, and anti-ingestion functions. Multiple functions can be achieved in a single application, simplifying the process and saving materials and processing costs. In addition, this multifunctional coating is an oil-based coating, so the repellent is not easily lost during long-term use.

[0009] Furthermore, the multifunctional coating covers the outer end face of the sealing ring and extends radially to completely cover the assembly gap between the sealing ring and the bent portion of the positive electrode shell and the negative electrode cover, so as to ensure that it completely covers the assembly gap between the positive electrode shell, the sealing ring and the negative electrode cover, and achieves the best sealing effect.

[0010] Furthermore, the UV slurry also includes a color developer in its raw material composition, wherein the color developer is present in an amount of 0-0.2 parts by weight. The addition of the color developer serves as a warning, allowing parents or caregivers to promptly detect if a child has come into contact with or accidentally ingested the battery. This warning effect is achieved through the color developer: when the color developer comes into contact with bodily fluids such as saliva, it forms a clear staining mark on the child's mouth, hands, and other areas, thus providing a visual warning. To avoid a decrease in color fixation depth due to excessive addition of the color developer, this invention controls the amount of the color developer to 0-0.2 parts by weight. In specific implementation, the color developer can be selected from one or a combination of multiple options of phthalocyanine blue, permanent red, Prussian blue, anthraquinone red, and azo red. Phthalocyanine blue, permanent red, Prussian blue, anthraquinone red, and azo red are all conventional color developers and are commercially available.

[0011] Furthermore, the acrylate prepolymer can be one or a combination of BR5006, BR5001, BR6103, M1063, and BR6104. BR5006, BR5001, BR6103, M1063, and BR6104 are all conventional acrylate prepolymers for UV adhesives and are commercially available.

[0012] Furthermore, the acrylic monomer can be selected from one or a combination of more of HEA, ACMO, CTFA, IBOA, DMAA, and THFA. HEA, ACMO, CTFA, IBOA, DMAA, and THFA are all common acrylic monomers for UV adhesives and are commercially available.

[0013] Furthermore, the photoinitiator can be selected from one or a combination of MBF, 184, TPO-L, and 819. MBF, 184, TPO-L, and 819 are all conventional photoinitiators for UV adhesives and are commercially available.

[0014] Furthermore, the leveling agent can be selected from one or a combination of UV3505, 493, 495, and 499. UV3505, 493, 495, and 499 are all conventional leveling agents for UV adhesives and are commercially available.

[0015] Furthermore, the aversive agent may be selected from one or more combinations of taste aversive agents, odor aversive agents, and tactile aversive agents. The taste aversive agent may be selected from one or a combination of two of denatonium benzoate and sucrose octaacetate; the odor aversive agent may be selected from one or a combination of two of allyl isothiocyanate, allicin, and onion extract; the tactile aversive agent may be selected from one or a combination of two of capsaicin, piperine, menthol, and food-grade camphor. All of the above aversive agents are conventional aversive agents and are commercially available.

[0016] In the specific implementation process, the multifunctional coating is formed by spraying the liquid adhesive onto the R-corner transition interface and then curing it by ultraviolet light irradiation. Attached Figure Description

[0017] Figure 1 This is an axial cross-sectional view of the control group's button cell structure. Figure 2 This is an axial cross-sectional view of the button cell with a multifunctional coating as described in an embodiment of the present invention. Figure 3 This is a top view of the button cell with a multifunctional coating as described in an embodiment of the present invention. Figure 4 This is a comparison of the appearance of button batteries before and after storage, for the control group; among them Figure 4-1 This is a photograph of the battery's appearance before it was stored at 60°C and 90% relative humidity. Figure 4-2 These are exterior photos stored under the same conditions. Figure 4-2 Area A in the middle is where green mold is more clearly produced; Figure 5 This is a comparison of the appearance of the button battery before and after storage according to an embodiment of the present invention; wherein... Figure 5-1 This is a photograph of the battery's appearance before it was stored at 60°C and 90% relative humidity. Figure 5-2 These are photos of the appearance after being stored under the same conditions. Detailed Implementation

[0018] The preferred embodiments of the button cell battery with a multifunctional coating of the present invention will be described in detail below with reference to the accompanying drawings.

[0019] Example 1 Taking the CR2032 button cell as an example, combined with Figure 2 and Figure 3The button cell with multifunctional coating includes a battery casing composed of a positive electrode shell 10, a sealing ring 20, and a negative electrode cover 30. The outer end of the positive electrode shell 10 is bent inward to form a bent section 11. The bent section 11 presses the sealing ring inward to achieve a sealed fit between the positive electrode shell 10, the sealing ring 20, and the negative electrode cover 30. The outer surface 110 of the end of the bent part 11 of the positive electrode shell, the outer end face 21 of the sealing ring, and the outer peripheral surface 31 of the negative electrode cover are sequentially connected to form an R-angle transition connection surface 100. A multifunctional coating 40 is provided on the R-angle transition joint surface 100; the multifunctional coating 40 is applied in a ring along the circumference of the battery. The multifunctional coating 40 covers the outer end face of the sealing ring 20 and extends radially to completely cover the assembly gap between the sealing ring 20 and the positive electrode shell bending portion 11 and the negative electrode cover 30 (i.e., it extends radially outward to completely cover the assembly gap between the sealing ring 20 and the positive electrode shell bending portion 11, and extends radially inward to completely cover the assembly gap between the sealing ring 20 and the negative electrode cover 30). The multifunctional coating 40 is formed by spraying a liquid adhesive onto the R-corner transition surface 100 and then subjecting it to cross-linking and curing by ultraviolet light irradiation; wherein the liquid adhesive is prepared by mixing the following raw materials in parts by weight: 52 parts of acrylate prepolymer BR5006; 44.75 parts of acrylic monomer ACMO; 5 parts of photoinitiator TPO-L; Leveling agent UV493, 0.15 parts; One part of the antagonist, benzyldenafil; Color developer: 0.1 parts azo red; All of the above raw materials are conventional preparations.

[0020] Other embodiments and comparative examples of button batteries with multifunctional coatings of the present invention differ from Example 1 only in the formulation of the liquid adhesive, the specific composition of which is shown in Table 1; the coating structure and its molding process are exactly the same as those of Example 1.

[0021] Table 1

[0022] For the liquid adhesives used in the above embodiments and comparative examples, a dispensing machine was used to uniformly coat the circumferentially connected surface of the button cell's R-corner transition joint. The leveling and molding effects of the adhesive are shown in Table 2. "Meets 3M 600 tape requirements" means that after the product coating is tested for adhesion with 3M 600 test tape, there is no peeling or flaking, and the adhesion is qualified.

[0023] Table 2

[0024] As can be seen from Tables 1 and 2, when the raw materials of the liquid adhesive are controlled according to the requirements of this invention (as in Examples 1-7), uniform distribution can be achieved, and the adhesive can be completely cured after ultraviolet irradiation, exhibiting good adhesion and ensuring a noticeable bitter taste. When the acrylate prepolymer is added to more than 75% (as in Comparative Example 1), the viscosity of the adhesive will be too high, affecting the leveling properties of the adhesive on the battery surface and causing the battery to have a poor appearance. Conversely, when the acrylate prepolymer is added to less than 40% (as in Comparative Example 2), or when too much leveling agent is added (as in Comparative Example 5), the adhesion effect of the cured multifunctional coating will not meet the requirements. When too little photoinitiator is added or too much repulsive agent is added (as in Comparative Examples 3 and 4), the curing will be severely affected. When too little color developer is added (as in Example 7), the color distribution of the adhesive layer will be uneven, affecting the appearance.

[0025] This invention presents an integrated multi-functional coating formed at the rounded transition surface of a button cell, providing sealing, insulation, and prevention of accidental ingestion. Multiple functions are achieved in a single application step, simplifying the process and saving materials and processing costs. Furthermore, this multi-functional coating is oil-based, preventing the repellent from easily dissipating during long-term use.

[0026] In addition, 60 button cells from Embodiment 1 of the present invention were taken, and an existing button cell with no coating on the R-corner transition joint surface was also taken (e.g. Figure 1 (As shown) 60 batteries served as a control group. Both groups of batteries were stored at 60℃ and 90% relative humidity for 14 days. Results showed that 13 of the 60 batteries in the control group exhibited mold growth, including green mold and white fuzz. The comparison before and after storage is shown below. Figure 4 As shown; however, none of the 60 batteries in Embodiment 1 of the present invention showed signs of mold growth, and their appearance before and after storage is shown in the following photos. Figure 5 As shown.

[0027] Figure 4 middle, Figure 4-1 This is a photograph of the battery's appearance before it was stored at 60°C and 90% relative humidity. Figure 4-2 These are exterior photos stored under the same conditions. Figure 4-2 Obvious green mold is visible at the R-corner transition joint surface of the battery.

[0028] Figure 5 middle, Figure 5-1 This is a photograph of the battery's appearance before it was stored at 60°C and 90% relative humidity. Figure 5-2 These are photos showing the appearance of the battery after being stored under the same conditions. There were no obvious changes in the battery's appearance, and no mold was observed.

[0029] In the specific implementation process, the color developer can be selected from one or more of phthalocyanine blue, permanent red, Prussian blue, anthraquinone red, and azo red, or other color developers for battery coatings. Phthalocyanine blue, permanent red, Prussian blue, anthraquinone red, and azo red are all conventional color developers and are commercially available; moreover, these color developers have high purity, extremely low toxicity or even are practically non-toxic, and are hardly decomposed or absorbed after entering the human body. The amount used in a single battery is only about 10 μg, far below the safety risk threshold of 1g.

[0030] The acrylate prepolymer can be selected from one or more of BR5006, BR5001, BR6103, M1063, and BR6104, or other acrylate prepolymers for UV adhesives. BR5006, BR5001, BR6103, M1063, and BR6104 are all conventional acrylate prepolymers for UV adhesives and are commercially available.

[0031] The acrylic monomer can be selected from one or more of HEA, ACMO, CTFA, IBOA, DMAA, and THFA, or other acrylic monomers for UV adhesives. HEA, ACMO, CTFA, IBOA, DMAA, and THFA are all common acrylic monomers for UV adhesives and are commercially available.

[0032] The photoinitiator can be selected from one or more of MBF, 184, TPO-L, and 819, or other photoinitiators for UV adhesives. MBF, 184, TPO-L, and 819 are all conventional photoinitiators for UV adhesives and are commercially available.

[0033] The leveling agent can be selected from one or more of UV3505, 493, 495, and 499, or other UV adhesive leveling agents. UV3505, 493, 495, and 499 are all conventional UV adhesive leveling agents and are commercially available.

[0034] The aversive agents can be selected from one or more combinations of taste aversive agents, odor aversive agents, and tactile aversive agents. The taste aversive agents can be selected from one or a combination of two of benzyl denatonium and sucrose octaacetate; the odor aversive agents can be selected from one or a combination of two of allyl isothiocyanate, allicin, and onion extract; the tactile aversive agents can be selected from one or a combination of two of capsaicin, piperine, menthol, and food-grade camphor. All of the above aversive agents are conventional and commercially available. Benzodyl denatonium has low toxicity, and sucrose octaacetate is essentially non-toxic; both are globally recognized as safe aversive agents / bittering agents. The remaining aversive agents also meet safety requirements. All of the above aversive agents are used in extremely low doses in the button battery coating, producing only a repulsive effect and posing no risk of poisoning to humans, thus meeting the safety requirements for preventing accidental ingestion.

[0035] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A button cell with a multifunctional coating, comprising a battery casing consisting of a positive electrode shell, a sealing ring, and a negative electrode cap, wherein the outer end of the positive electrode shell is bent inward to form a bent section, and the sealing ring is pressed inward by the bent section to achieve a sealed fit between the positive electrode shell, the sealing ring, and the negative electrode cap; the outer surface of the bent portion of the positive electrode shell, the outer end face of the sealing ring, and the outer peripheral surface of the negative electrode cap are sequentially connected to form an R-angle transition connection surface; characterized in that: A multifunctional coating is provided on the R-angle transition surface; the multifunctional coating is applied circumferentially along the battery circumference. The liquid adhesive for the multifunctional coating is prepared by mixing the following raw materials in parts by weight: 52-75 parts of acrylate prepolymer; 15-45 parts of acrylic monomer; Photoinitiator 0.5–5 parts; Leveling agent 0.05–0.2 parts; 0.4–5 parts of an aversive agent; The photoinitiator, leveling agent, and antagonist mentioned herein are all conventional commercial additives.

2. The button battery with a multifunctional coating according to claim 1, characterized in that: The multifunctional coating covers the outer end face of the sealing ring and extends radially to completely cover the assembly gap between the sealing ring and the bent part of the positive electrode shell and the negative electrode cover.

3. The button cell with a multifunctional coating according to claim 1, characterized in that: The raw material composition of the UV slurry also includes a color developer, which is 0 to 0.2 parts by weight.

4. The button cell with a multifunctional coating according to claim 3, characterized in that: The colorimetric agent is selected from one or a combination of multiple of phthalocyanine blue, permanent red, Prussian blue, anthraquinone red, and azo red.

5. The button cell with a multifunctional coating according to claim 1, characterized in that: The acrylate prepolymer is selected from one or more of BR5006, BR5001, BR6103, M1063, and BR6104.

6. The button cell with a multifunctional coating according to claim 1, characterized in that: The acrylic monomer is selected from one or a combination of more of HEA, ACMO, CTFA, IBOA, DMAA, and THFA.

7. The button cell with a multifunctional coating according to claim 1, characterized in that: The photoinitiator is selected from one or a combination of MBF, 184, TPO-L, and 819.

8. The button cell with a multifunctional coating according to claim 1, characterized in that: The leveling agent can be selected from one or a combination of more of UV3505, 493, 495, and 499.

9. The button cell with a multifunctional coating according to claim 1, characterized in that: The aversive agent is selected from one or more combinations of taste aversive agents, odor aversive agents, and touch aversive agents.

10. The button cell with a multifunctional coating according to claim 9, characterized in that: The taste aversive agent is selected from one or a combination of two of benzodiazepine and sucrose octaacetate; the odor aversive agent is selected from one or a combination of two of allyl isothiocyanate, allicin, and onion extract; the tactile aversive agent is selected from one or a combination of two of capsaicin, piperine, menthol, and food-grade camphor.

11. The button cell with a multifunctional coating according to claim 1, characterized in that: The multifunctional coating is formed by spraying the liquid adhesive onto the R-corner transition interface and then curing it through cross-linking caused by ultraviolet light irradiation.

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